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1.
A previous study by the authors showed that myocardial infarct size in the rabbit, measured after 45 mins of ischemia and 3 h of reperfusion, could be limited by administration of superoxide dismutase (SOD) plus catalase. The present study examined whether this infarct size limitation is sustained for the following three days. Under anesthesia, a coronary branch of the Japanese white rabbit was occluded for 45 mins and then reperfused. Three days after surgery, the heart was excised and the volume of myocardium supplied by the occluded coronary branch (ischemic zone size) was assessed with fluorescent particles and the infarct size was estimated by hematoxylin and eosin and with Mallory's staining. The SOD plus catalase group (n = 14) received 15,000 units/kg of SOD plus 50,000 units/kg of catalase in saline over 90 mins, starting 15 mins before the coronary occlusion. Saline was infused in the control group (n = 15). Three rabbits in the control group and three in the SOD plus catalase group died of ventricular fibrillation during the ischemic period. Three control and two SOD plus catalase rabbits were excluded because the ischemic zone was ambiguous. The percentage of the ischemic zone which was infarcted was 59.4 +/- 6.9% (mean +/- SE) in the control group (n = 9) and 49.4 +/- 5.1% in the SOD plus catalase group (n = 9). These were not statistically different. Ischemic zone size and hemodynamic parameters were similar in the two groups. These findings suggest that SOD plus catalase may serve only to delay rather than prevent myocardial infarction.  相似文献   

2.
The effects of physiological changes in estrogens and androgens on the erythrocyte antioxidant superoxide dismutase, catalase and glutathione peroxidase enzyme activities during the menstrual cycle were investigated in healthy eumenorrheic women. Blood samples were taken on alternate days from twelve normally cyclic women (age range: 20 to 27 years; mean age: 24.1 years) from the first day of one menstrual cycle until the first day of the subsequent one. Plasma was analyzed for FSH, LH, estradiol, progesterone, testosterone, free testosterone and androstenedione concentrations. Erythrocyte superoxide dismutase, catalase and glutathione peroxidase activities were evaluated on the same days and cycle length was standardized on the basis of the preovulatory estradiol peak. Significant cyclic phase-related changes were observed in glutathione peroxidase (P<0.05), with higher glutathione peroxidase activity levels from the late follicular to the early luteal phase compared with those found in the early follicular phase (P<0.001 and P<0.002 respectively). A significant positive correlation was observed between mean estradiol and glutathione peroxidase cycle-related variations (r=0.80, P<0.001), whereas no significant cycle phase-dependent changes were seen in superoxide dismutase and catalase. No effect of progesterone and androgens on the erythrocyte antioxidant enzyme system was documented. The findings indicate that physiological ovarian estradiol production during the menstrual cycle may have an important role in regulating erythrocyte glutathione peroxidase activity.  相似文献   

3.
CuZn superoxide dismutase, Mn superoxide dismutase, catalase and glutathione peroxidase activities in lymphocytes and erythrocytes were studied in 9 children with insulin-dependent diabetes mellitus (IDDM) as well as in 21 healthy children. The mean erythrocyte CuZn superoxide dismutase and glutathione peroxidase were statistically significantly lower in the IDDM group compared with the controls although almost all IDDM results fell within the mean +/- 2 SD limits of the controls. The small differences found can hardly be assigned biological significance. Erythrocyte catalase as well as lymphocyte CuZn superoxide dismutase and Mn superoxide dismutase did not differ from the controls.  相似文献   

4.
Increased oxidative stress has been implicated in the pathogenesis of chronic obstructive pulmonary disease (COPD). This study investigated the risk of COPD and the substitution of alanine 16 with valine (Ala16Val) polymorphism of manganese-superoxide dismutase (Mn-SOD) and the cytosine to thymidine transition of nucleotide -262 (-262C>T) polymorphism of the catalase gene, and the activity of erythrocyte SOD and catalase. The subjects were stable COPD patient ever smokers (n = 165) and healthy controls, matched for age and cigarette consumption. Genotyping of Mn-SOD at Ala16Val and the catalase gene at -262C>T was performed, and the functional activity of SOD and catalase in erythrocytes determined. There were no significant differences in the distribution of the different genotypes or allele frequencies between patients and controls for both the Mn-SOD and catalase genes. Among healthy controls or COPD patients, no differences were observed in erythrocyte SOD and catalase activity, irrespective of genotype. Significantly higher erythrocyte catalase activity was found in COPD patients than in healthy controls. The T/T catalase genotype and Ala/Ala Mn-SOD genotype were uncommon in the present Chinese population. The increase in erythrocyte catalase activity in Chinese patients with chronic obstructive pulmonary disease probably indicates dysfunction of the oxidant/antioxidant defence system, but it is unclear whether this increase is compensatory or a pathogenic factor.  相似文献   

5.
Induction of superoxide dismutase in Escherichia coli by heat shock.   总被引:18,自引:1,他引:18       下载免费PDF全文
Exposure of midlogarithmic-phase cultures of Escherichia coli B to 48 degrees C for 1 hr elicited an induction of the manganese-containing superoxide dismutase (MnSOD), which became more pronounced during 1 hr of recovery at 37 degrees C. This induction required protein biosynthesis, since it was suppressed by chloramphenicol. Induction of MnSOD appeared to be a response to a heat-mediated increase in O2- production because it was dioxygen-dependent and because heating to 48 degrees C doubled the cyanide-resistant fraction of the total respiration.  相似文献   

6.
Summary It has been reported that agents having the ability to scavenge oxygen-derived free radicals reduce the severity of ventricular arrhythmias that occur after brief coronary occlusion and reperfusion. Superoxide dismutase plus catalase (SOD + CAT) or placebo was administered in a blinded randomized fashion prior to coronary occlusion in rats (n = 25 each group) undergoing a 5-min left coronary occlusion followed by 15 min of reperfusion. During reperfusion, ventricular tachycardia (VT) developed in 96 % of animals in both groups. Reperfusion ventricular fibrillation (VF) developed in 60 % of the placebo group vs 56 % in the SOD + CAT group (p =1.0). Irreversible VF occurred in 40 of the placebo group vs 20 % in the SOD + CAT group (p = 0.22). Atrioventricular block occurred in 12 % of placebo and 4 % of SOD + CAT animals (p = 0.61).There were no significant differences between groups in duration of VT (85 ± 15 s (mean ± SEM) placebo vs 81 ± 14 s SOD + CAT, p = 0.81), total duration of VT plus VF (391 ± 76 s placebo vs 256 ± 64 SOD + CAT, p = 0.45) or numbers of single ventricular ectopic beats (65 ± 15 placebo vs 97 ± 18 SOD + CAT, p = 0.18). Heart rate at reperfusion was slightly higher in control than SOD + CAT animals (340 ± 33 vs 319 ± 32, p = 0.02). Risk zone size, determined by Monastral blue injection, was equal in both groups (34 ± 2 % of ventricular mass). The occurrence of reperfusion VF in this model could not be predicted by heart rate at reperfusion (331 ± 33 VF animals vs 328 ± 36 no VF, p = 0.77), or by risk zone size (34 ± 2 %, VF and no VF groups).Treatment with SOD + CAT did not reduce the overall incidence or duration of reperfusion arrhythmias in this model, though such treatment was associated with a non-significant trend toward less irreversibility of VF.Supported in part by National Institutes of Health SCOR HL-26215, Bethesda, Maryland 660  相似文献   

7.
The primary objective of this study was to determine the effect that the xanthine oxidase inhibitor allopurinol (ALLO) and the hydrogen peroxide scavenger catalase (CAT) have on the cardiovascular compensatory ability of the dog to respond to severe hemorrhagic hypotension. Twenty-four mongrel dogs were anesthetized with sodium pentabarbitol and surgically prepared to monitor 1) average arterial blood pressure (AAP), 2) central venous pressure (CVP), 3) heart rate (HR), 4) cardiac index (CI = CO/kg), and hindlimb skeletal muscle blood flow (MBF). Total body vascular conductance (TBC) and skeletal muscle vascular conductance (MVC) were calculated by dividing the CI or MBF by the difference between the AAP and CVP. Eight animals were placed into each of the following three groups, bled over a 1-hr period of time to an AAP of 50 mm Hg and monitored for an additional 2 hr. Group I controls received an intravenous volume of lactated Ringer's equivalent to that volume given to groups II and III. Group II was pretreated 24 hr prior to hemorrhage with 100 mg/kg ALLO orally and received a bolus injection of 25 mg/kg 15 min prior to hemorrhage plus an intravenous infusion of 5 mg/kg/hr over the 3-hr study. Group III was given the same ALLO treatment as group II plus an additional 5-mg/kg/hr intravenous infusion of CAT throughout the duration of the 3-hr study. The results show that the intense compensatory increase in total body vascular tone which occurs during severe hypovolemia is significantly reduced at the 60-, 120-, and 180-min periods in the ALLO/CAT group; however, when ALLO alone was used this effect lasted only through the 120-min period. A similar, but statistically less convincing, picture was seen in the skeletal muscle vascular bed. Thus, the ALLO/CAT group seemed to inhibit some free radical mechanisms better than the ALLO group during and immediately following hemorrhage. Allopurinol alone lost its effectiveness before the 3 hr, which suggests that a free radical mechanism may play an early role in the pathophysiologic shock sequence. As shock continues, however, other factors seem to override the free radical mechanism. One possible explanation for this early tissue protective action of allopurinol and catalase is the inhibition of the oxygen free-radical-induced microvascular swelling and plugging.  相似文献   

8.
The aim of the present study was to evaluate the effects of hyaluronan (HA) on nitric oxide (NO) levels and superoxide dismutase (SOD) enzyme activities in synovial fluid (SF) in the treatment of patients with knee osteoarthritis (OA). SF samples were aspirated from OA patients before the commencement of the treatment (n = 23) and 6 weeks after they were treated with HA products. NO levels and SOD activities were compared between the pre- and post-treatment of OA patients and of the control group (n = 10). SF NO levels were significantly higher in patients with OA before the commencement of the treatment compared with the post-treatment (p < 0.001) and the control groups. The SF SOD activity of patients before the commencement of the treatment was lower than the values in the controls and post-treatment (p < 0.001). There is no significant correlation between SF NO and SOD levels and the radiographic changes of the OA knee according to Kellgren–Lawrence grading (p > 0.05). Also, the Western Ontario and McMaster Universities Osteoarthritis index (WOMAC) pain scores and physical function scores were gradually improved. These findings made us think that SF NO was a potent mediator in cartilage damage in OA, whereas SOD was an antioxidant mediator in the same process. Exogenous HA injections might reduce the NO levels and increase SOD activities in synovial fluid. These effects also do not seem to be dependent on the radiographic grading of the OA knee. More comprehensive studies are needed to clarify a possible clinical significance of this topic, and we suggest that this is an important area for further research into new treatment options.  相似文献   

9.
Summary The anti-neoplastic activity of N-[N-(2-chloroethyl)-N-nitrosocarbamoyl(CNC)]-alanine, CNC-alanyl-alanine, CNC-alanine-methylamide and CNC-glycine-methylamide was examined in murine transplantable colon tumours (MAC). The methylamide derivatives were highly active against a solid adenocarcinoma (MAC 13) and an ascitic adenocarcinoma (MAC 15A). CNC-alanyl-alanine was also highly active against MAC 15A. Responses of the three latter agents against the ascitic tumour were better than for any previously tested drugs including the nitrosoureas but their eventual usefulness cannot be determined without further toxicological studies.This work was supported by the Turner/Whyte Watson Cancer Research Trust (Bradford) and was undertaken within the Screening and Pharmacology Group of the EORTC  相似文献   

10.
The activities of superoxide dismutase, glutathione peroxidase (GPX) and catalase--the enzymatic scavengers of reactive oxygen species and the activities of xanthine oxidoreductase and xanthine oxidase, an enzyme known to generate reactive oxygen species, were studied in the corneas of normal rabbit eyes of various ages (1 month--young eyes; 4-9.5 months--young adult eyes; 2.0-2.75 years--middle aged eyes; 3.0-5.0 years--aged eyes). The activities of GPX, superoxide dismutase, xanthine oxidoreductase and xanthine oxidase were investigated biochemically in the scraped corneal epithelium. Catalase activity was detected histochemically in the corneal epithelium and endothelium. The results show that young corneas revealed lower activities of all the antioxidant enzymes investigated than did young adult corneas, in which enzymatic activities reached their maximum. In middle-aged corneas, GPX and catalase activities remained approximately at the same levels as seen in young adult corneas, whereas superoxide dismutase activity was decreased. In aged corneas, the activities of all antioxidant enzymes were dramatically decreased or even lost (catalase activity in the corneal endothelium). In contrast, xanthine oxidoreductase activity only slightly decreased with age and the xanthine oxidase proportion of total xanthine oxidoreductase remained unchanged. GPX, superoxide dismutase and catalase are important antioxidant enzymes protecting the cornea against the oxidative damage. Because the activities of these enzymes are lower in young animals and greatly reduced in aged animals, it is suggested that young and particularly aged corneas might be more susceptible to oxidative stress than are young adult corneas. This presumption is supported by the fact that the activities of prooxidant enzymes (xanthine oxidoreductase/xanthine oxidase) are only slightly decreased in aged corneas as compared to young adult corneas so that some imbalance between antioxidant and prooxidant enzymes exists already in the normal aged corneas.  相似文献   

11.
ObjectivesA member of the second-generation sulfonylureas, glyburide (GLY; glibenclamide) provides an effective therapy for patients with type 2 diabetes. It stimulates pancreatic insulin secretion, suggesting that it is effective in the treatment of type 2 diabetes primarily by elevating the circulating insulin levels. However, experimental evidences have indicated that sulfonylureas have also had an extrapancreatic effect, which may directly contribute toward maintaining blood glucose homeostasis during diabetes.MethodsIn this study, we administrated GLY to streptozotocin-induced diabetic rats and determined the effects of such treatment on activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) from brain tissue.Results and DiscussionBrain CAT and GPx activities were not significantly different in the diabetic group compared to controls (P>.05), but the SOD activity was significantly reduced in the diabetic group compared to controls (P<.001). GLY treatment of 4 weeks had restored the SOD and CAT enzyme activities in diabetic rat brain (P<.05). In addition, high blood glucose levels of untreated diabetic rats were decreased following the GLY treatment (P<.01). Administration of GLY to diabetic rats restored the diabetes-induced changes, suggesting that GLY could restore the brain SOD and CAT activities.  相似文献   

12.
Therapy directed against the toxic effects of reactive oxygen species may reduce the final extent of ischemic injury in otherwise viable tissue irreversibly injured by the abrupt reoxygenation of reperfusion. In four groups of dogs, superoxide dismutase plus catalase (groups I-III) or saline (controls) (group IV) was infused into the left atrium. Group I received the infusion for 2 hours, beginning 15 minutes before occlusion of the left circumflex coronary artery (90 minutes) and ending 15 minutes after reperfusion. Group II received the infusion for 1 hour starting 15 minutes before reperfusion. Group III received the infusion for 1 hour beginning 40 minutes after reperfusion. Dogs were killed the next day, and infarct size was determined by dissection and weighing, and confirmed histologically. Infarct size expressed as percent of the anatomic area at risk was: group I, 19.4 +/- 5.0; group II, 21.8 +/- 3.3; group III, 47.6 +/- 10.3; group IV, 43.6 +/- 3.5 (mean +/- SEM). Analysis of variance followed by Duncan's multiple range test showed that ultimate infarct size as assessed in groups I and II differed significantly (P less than 0.05) from that observed in the control animals in group IV, whereas infarct size between groups III and IV did not differ significantly (P greater than 0.05). The percent of left ventricle at risk did not differ between the four groups. The beneficial effects of superoxide dismutase plus catalase could not be explained by hemodynamic differences. Similar protection of jeopardized myocardium in groups I and II suggest that potentially viable tissue is salvaged by scavenging free radicals during early reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

13.
BACKGROUND: Reactive oxygen species (ROS) production increases after injury and potentially contributes to restenosis after angioplasty. We therefore evaluated the effect of adenovirus-mediated gene transfer (Ad) of superoxide dismutase (SOD) and catalase (CAT) on ROS production and restenosis after balloon angioplasty. METHODS: O(2)(-) and H(2)O(2 )production was quantified in cultured cells after incubation with either LPS or CuSO(4). Angioplasty and gene transfer were performed in rabbit atherosclerotic iliac arteries. One artery was injected with AdSOD and AdCAT, while the contralateral artery was injected with an adenovirus carrying no transgene, and served as control. RESULTS: ROS production was significantly decreased after adenovirus-mediated gene transfer of SOD and CAT as compared with control. Treated arteries showed less restenosis (32 +/- 27 vs. 63 +/- 19%, p = 0.003) and less constrictive remodeling (1.2 +/- 0.3 vs. 0.9 +/- 0.2, p = 0.02) than control arteries. Arteries injected with AdSOD and AdCAT showed better vasoreactivity to acetylcholine (11 +/- 4 vs. -1 +/- 6%, p < 0.05), lower collagen density (43 +/- 16 vs. 53 +/- 23%, p = 0.03), and lower inflammatory cell infiltration (22 +/- 6 vs. 36 +/- 11%, p = 0.04) than control arteries. CONCLUSIONS: Our data suggest that adenovirus-mediated gene transfer of SOD and CAT reduced oxidative stress, restenosis, collagen accumulation, and inflammation and improved endothelial function after angioplasty.  相似文献   

14.
Summary The antibody to 65 KD mycobacterial heat shock protein (HSP65) and antibody to human superoxide dismutase (H-SOD) were measured by ELISA in patients with autoimmune hepatitis (AIH), and results were compared with those of patients with chronic active hepatitis C (CAH-C) or systemic lupus erythematosus (SLE) and normal subjects (NS). Patients with AIH had significantly higher OD values of anti-HSP65 antibody and anti-H-SOD antibody compared with those of patients with CAH-C or SLE and NS. OD values of anti-HSP65 antibody were correlated with those of anti-SOD antibody. Affinity-purified anti-SOD antibody reacted with HSP65. Analysis of the amino acid sequence of human SOD showed that 7 segments, corresponding to r to 25 amino acid residues, exhibited 50 to 71% homology with that of mycobacterial HSP65.  相似文献   

15.
16.
It has already shown that catalase activity is significantly decreased in red cells of patients with P. falciparum. The mechanism suggested was by this enzyme inactivation through increased H2O2 generated during malarial infection. The present study was performed to verify this hypothesis. Catalase activities of red cells with high or low parasitemia in patients with P. falciparum were found to be lower than those of normal red cells. However, P. falciparum-infected red cells cultured for one week showed similar SOD and catalase levels to normal red cells. There was also no significant difference in the catalase levels between the parasitized and non-parasitized red cells. The difference in catalase activity of infected red cells before and after culture could be explained in terms of the activation of mononuclear cells and macrophages in vivo. During the sojourn of the parasitized red cells in close proximity to the macrophages of the spleen, they might trigger oxidative bursts resulting in increased H2O2. In order to protect themselves from oxidant damage, the catalase in the infected red cells could be inactivated by H2O2 resulting in the reduction of this enzyme.  相似文献   

17.
The effect of the enzyme superoxide dismutase (SOD) on experimentally induced osteoarthritis was investigated. Immobilization of the right knee of rabbits over variable periods (1-4 weeks) was used as the model for the study. SOD was applied intraarticularly. Distinct histological changes were detected in the immobilized joints in contrast to the freely mobile joints. In the group of rabbits treated with SOD, erosions, necroses, and inflammatory symptoms were more frequent than in the placebo group. The changes found in animals after SOD application indicate the enzyme has an intensifying effect on osteoarthritis.  相似文献   

18.
Relationship of superoxide dismutase and catalase activities and aging were tested using bean weevil lines selected for postponed senescence. The beetles of different age (young and old) and mating status (virgin and mated) from the extended longevity lines were compared with their counterparts derived from the short-lived lines for activities of SOD and catalase. The old beetles from the long-lived lines had statistically significant higher activity of SOD than their controls. Although we did not find a significant effect of catalase on longevity, beetles originating from both types of lines exhibited an increased catalase activity during mating processes. In addition, we did observe an increased activity of catalase in one-day-old beetles of the short-lived lines relative to the same-aged individuals of the long-lived lines.  相似文献   

19.
The number of alveolar macrophage (AM) and activity of superoxide dismutase (SOD) and catalase (CA) in AM and obtained from bronchoalveolar lavage (BAL) were assayed in 11 lung cancer patients and 21 patients without lung cancer. The SOD, CA activities was lower in the patients with lung cancer than that in patients without lung cancer. The number of AM in BAL reduced too. It suggested that metabolism of AM was inhibited seriously in patients with lung cancer. The number of AM in BAL of smokers was significant higher than that of non-smokers, and it is postulated that the increase of AM is probably the result of stimulation induced by smoking.  相似文献   

20.
Scavengers of toxic oxygen reduction products have been reported to reduce the inflammatory reaction in some models of pancreatitis. In a blinded study, the effect of parenteral pretreatment with superoxide dismutase plus catalase was compared with placebo on pancreatitis induced in rats by infusion of 0.25% or 2% sodium taurocholate into the hepatopancreatic duct. The degree of inflammation was assessed by macroscopic examination of the pancreas, dry/wet weight ratios of pancreatic specimens, amylase activity in plasma and peritoneal exudate, the weight of the exudate, and its content of total protein. All parameters were indicative of a more severe inflammation in rats given the higher concentration of sodium taurocholate. The only significant effect of the superoxide dismutase plus catalase treatment was a moderate reduction of the dry/wet weight ratio, i.e., pancreatic edema, in rats given 2% sodium taurocholate. Our results indicate that toxic oxygen reduction products, available for interception by parenterally administered superoxide dismutase plus catalase, are of only minor importance in the pathogenesis of sodium taurocholate-induced pancreatitis in the rat.  相似文献   

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